I'll tell you the strategy that worked for me last time (quit for ~2 years), and that I'm using this time.

• Switch to a vape. Lung capacity increases immediately, and you get rid of the bad smell. If you haven't vaped, give yourself some time to get used to the different habit (no cigarette packing ritual anymore etc)
• Buy a 0 nicotine vape or two, or find a local place you can get them easily. This is your "inside" vape.
• Buy a refillable vape and get nicotine liquid roughly equivalent to the full-nic vape you switched to from cigarettes. This is your "outside" vape.
• Start restricting the locations you use the full-nic vape. I work from home, so I don't vape full-nic at my desk, I walk outside to do it. You want to break the absent-minded vaping+work or vaping+tv habit.
• Step your nicotine intake down over as long a period as you like, but don't ever step it back up. First time I quit, I did it over about a year. That's a little extreme. You could probably do it over a few months.
• Once you're on 0 nic all the time, either stay with that, or gradually wean yourself off the habit as well. This is much easier without the chemical addiction.

Good luck.